Partners' Capital, Equity and Incentive Compensation Plans (Summary of Award Activity Under 2010 Equity Incentive Plan and 2013 Equity Incentive Plan and Related Information) (Details) - $ / shares	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
2010 Equity Incentive Plan | Class O Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Beginning balance, number of units (in shares)	82,310	102,279	568,040
Number of units, granted (in shares)	0	0	0
Number of units, exercised/vested (in shares)	(6,875)	(19,969)	(465,761)
Number of units, cancelled/expired (in shares)	0	0	0
Ending balance, number of units (in shares)	75,435	82,310	102,279
Beginning balance, weighted average exercise price units (in dollars per share)	$ 24.97	$ 24.05	$ 23.52
Weighted average exercise price units, granted (in dollars per share)	0	0	0
Weighted average exercise price units, exercised (in dollars per share)	25.00	20.25	23.40
Weighted average exercise price units, cancelled/expired (in dollars per share)	0	0	0
Ending balance, weighted average exercise price units (in dollars per share)	25.00	24.97	24.05
Beginning balance, weighted average fair value (in dollars per share)	5.97	5.67	5.00
Weighted average fair value, granted (in dollars per share)	0	0	0
Weighted average fair value, exercised (in dollars per share)	4.49	4.42	4.76
Weighted average fair value, cancelled/ expired (in dollars per share)	0	0	0
Ending balance, weighted average fair value (in dollars per share)	$ 6.11	$ 5.97	$ 5.67
2013 Equity Incentive Plan | Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Beginning balance, options outstanding (in shares)	1,934,838	2,037,163	1,369,270
Options, granted (in shares)	99,872	135,594	674,081
Options, exercised (in shares)	(98,303)	(125,213)	(6,188)
Options, cancelled/expired (in shares)	0	(112,706)	0
Ending balance, options outstanding (in shares)	1,936,407	1,934,838	2,037,163
Beginning balance, weighted average exercise price options outstanding (in dollars per share)	$ 37.11	$ 36.86	$ 38.18
Weighted average exercise price options outstanding, granted (in dollars per share)	56.84	42.27	34.05
Weighted average exercise price options outstanding, exercised (in dollars per share)	28.84	30.80	21.50
Weighted average exercise price options outstanding, cancelled/expired (in dollars per share)	0	45.86	0
Ending balance, weighted average exercise price options outstanding (in dollars per share)	38.55	37.11	36.86
Beginning balance, weighted average fair value, options (in dollars per share)	7.05	7.10	7.80
Weighted average fair value, granted, options (in dollars per share)	9.35	7.62	5.63
Weighted average fair value, vested, options (in dollars per share)	5.18	6.21	3.68
Weighted average fair value, cancelled/expired, options (in dollars per share)	0	9.43	0
Ending balance, weighted average fair value, options (in dollars per share)	$ 7.26	$ 7.05	$ 7.10
2013 Equity Incentive Plan | Restricted Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Beginning balance, number of units (in shares)	389,750	420,309	381,864
Number of units, granted (in shares)	302,591	274,564	348,152
Number of units, exercised/vested (in shares)	(264,466)	(279,429)	(224,660)
Number of units, cancelled/expired (in shares)	(11,379)	(25,694)	(85,047)
Ending balance, number of units (in shares)	416,496	389,750	420,309
Beginning balance, weighted average exercise price units (in dollars per share)	$ 39.67	$ 37.83	$ 46.37
Weighted average exercise price units, granted (in dollars per share)	57.47	42.25	35.27
Weighted average exercise price units, exercised (in dollars per share)	39.89	39.20	46.23
Weighted average exercise price units, cancelled/expired (in dollars per share)	49.38	42.17	43.50
Ending balance, weighted average exercise price units (in dollars per share)	$ 52.20	$ 39.67	$ 37.83
2013 Equity Incentive Plan | Performance-Based Relative TSR Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Beginning balance, number of units (in shares)	84,350	0	0
Number of units, granted (in shares)	84,202	86,089	0
Number of units, exercised/vested (in shares)	0	0	0
Number of units, cancelled/expired (in shares)	0	(1,739)	0
Ending balance, number of units (in shares)	168,552	84,350	0
Weighted average exercise price units, exercised (in dollars per share)	$ 0	$ 0	$ 0
Beginning balance, weighted average fair value, options (in dollars per share)	54.64	0	0
Weighted average fair value, granted, options (in dollars per share)	79.18	54.64	0
Weighted average fair value, cancelled/expired, options (in dollars per share)	0	54.64	0
Ending balance, weighted average fair value, options (in dollars per share)	$ 66.90	$ 54.64	$ 0
2013 Equity Incentive Plan | Performance-Based FFO Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Beginning balance, number of units (in shares)	84,350	0	0
Number of units, granted (in shares)	84,202	86,089	0
Number of units, performance adjustment (in shares)	59,844
Number of units, exercised/vested (in shares)	(96,129)	0	0
Number of units, cancelled/expired (in shares)	0	(1,739)	0
Ending balance, number of units (in shares)	132,267	84,350	0
Weighted average exercise price units, performance adjustment (in dollars per share)	$ 42.01
Weighted average exercise price units, exercised (in dollars per share)	42.01	$ 0	$ 0
Beginning balance, weighted average fair value, options (in dollars per share)	42.01	0	0
Weighted average fair value, granted, options (in dollars per share)	56.84	42.01	0
Weighted average fair value, cancelled/expired, options (in dollars per share)	0	42.01	0
Ending balance, weighted average fair value, options (in dollars per share)	$ 51.45	$ 42.01	$ 0